Original Open Access

A rare sugar, 6-deoxy-d-altrose, isolated from a polysaccharide extracted from an edible folk medicinal mushroom (Lactarius akahatsu) was identified using 1 H and 13 C-NMR including 2D-COSY and 2D-HSQC spectroscopy, and specific rotation. The 6-deoxy-sugar isolated from the acid hydrolysate of the polysaccharide extracted from L. akahatsu was involved in four anomeric isomers (α- and β-pyranose, and α-and β-furanose) in aqueous solution due to mutarotation. Almost all of the signals from the 1D ( 1 H- and 13 C-) and 2D (COSY and HSQC)-NMR spectra of the 6-deoxy-sugar agreed with the data from the authentic 6-deoxy- daltrose. The specific rotation [α] 589 of the 6-deoxy-sugar isolated from L. akahatsu was +17.6 0 . Thus, the 6-deoxy-sugar isolated from Lactarius akahatsu was identified as 6-deoxy-d-altrose.